Fennec 1.0 beta 1, the newest version of Firefox for mobile, has just been released for download by Mozilla, and its features ought to have even desktop browsers worried. Read on for full details plus a video of Fennec in action.

We’ve been charting Fennec‘s progress from the early alpha version to its first steps on Windows Mobile, but now it’s been released as Fennec 1.0 beta 1 for the Nokia N810, and the features it packs should have Opera and other mobile browser developers looking to it for inspiration.

Fennec 1.0 beta 1 is strikingly similar to Firefox 3: as well as third party plug-in support (gesture support is one of the first plug-ins for Fennec 1.0 beta 1), there’s the Awesome Bar, a clever URL address and search bar in one.

There are also some speedy page rendering skills. But it’s the add-on options that have got us excited. Potentially, you’ll be able to bolt on everything from Twitter updates to image editing apps within the browser.

Fennec 1.0 beta 1 is available for download for testing purposes if you’ve got a Nokia N810 right now, and you can see a video of Fennec 1.0 beta 1 in action below. The ball’s in your court, Opera.